In the Electronics Industry quite commonly specialty businesses do various steps in the manufacturing and packaging of chips, in imaging, development and manufacturing of circuit boards and in mounting of components on a board, In a system of this type, maintaining proper inventory, transportation and communications are inherently difficult. Further much of the business is overseas because of lower cost labor. There is a need for an integrated process that may be automated to make labor cost a minor cost element Further there is an ever increasing need for greater component density on a circuit board allowing developments such as smaller more powerful lap-top computers.
This invention addresses the needs as outlined by uniquely modifying chip packaging and circuit board manufacture to use a high density circuitry with no thru hole connector and to allow simple in-process testing and machine mounting to mount any of a variety of chips in a package designed to allow stacking of multiple chips or to mount directly to the board. Both chip packaging and board manufacture are designed to minimize manual labor to essentially machine oversight.
Unique features include formation of metallic leads with gold being preferable that may be 0.5 mil. or smaller on tape with one end of the leads positioned for contacting a pad on a chip and the other end positioned for contacting rigid conductive contactors on a ceramic or plastic package with leads so positioned as to allow pressure mounting or thermocompression bonding of all leads at one time. Further the package design includes connectors and contactors so that with a simple solder dip the inputs and outputs from chips, or in chip packages stacked adjacent to each other, may be used. The circuit board is made with circuitry with leads as small as one mil. and as close as two mils. apart separated by a photoimagable plastic dielectric from closely packed circuitry running essentially transverse. The circuitry is integrally formed by electroplating. The double layer circuitry, as descried, may be used to form circuitry for mounting chips and components on either one or on both sides of the board. Edge connectors connect circuitry on each side of the board where needed. This design eliminates thru hole connectors with attendant problems and provides for greater component part board density by having one portion of essentially undirectional circuitry separated from another by a photoimageable plastic film thereby allowing connection by plating to circuitry that may be quite dense in a transverse direction. The board circuitry may be likened to struts laid out very close together wherein struts in one direction are separated from cross struts by insulators with connectors allowing one to change levels.
We have considered the following patents:
______________________________________ Patent No. Date Inventor ______________________________________ 4,433,886 2/28/84 J. W. Cassarly et al 3,906,144 9/16/75 David Wiley 4,511,201 4/16/85 Baker et al 4,176,201 12/4/79 L. D. Aldridge 4,390,220 6/28/83 J. E. Benassutte 4,374,080 2/15/83 Jon M. Schroeder 4,449,690 5/22/84 Jon M. Schroeder 4,438,181 3/20/84 Jon M. Schroeder 4,616,412 10/14/86 Jon M. Schroeder 4,688,150 8/18/87 R. K. Peterson 4,330,812 5/18/82 R. H. Token 60-225,966 11/11/85 K. K. Canon & Hideo Fushimato 52-74637 1/23/79 Nippon Denki and Akihiro Doutani 3,335,371 8/8/67 N. F. Damon et al 4,164,003 8/7/79 M. Cutchaw RE. 31,114 12/28/82 W. E. Berg 3,335,327 8/8/67 N. T. Damon et al 4,366,777 12/2/80 J. F. Merlinu et al 4,169,642 10/2/79 Bob Mouissie 4,166,665 9/4/79 J. M. Cutchaw 3,571,915 3/23/71 F. A. Shirland 4,494,688 1/22/85 Hatada et al Ser No. 5/30/89 Jon M. Schroeder 07/358,503 ______________________________________